Research On Thermo-mechanical Coupling Characteristics For Linear Rolling Guideway Of CNC Machine Tool

The final machining accuracy and overall performance of the machine tool has been influenced by thermo-mechanical coupling characteristics of the feed system more and more obviously with the continuous improvement of the machine tool accuracy.The linear rolling guideway is one of the common key components of the CNC machine tool feed system,so it has important significance to study its thermo-mechanical coupling characteristics for further research on the influence of feed system on the machine tool and improving performance of the whole machine tool.The linear rolling guideway of HSR series produced by a company was taken as the research object of the paper,and the key technical problems in the process of modeling and simulation of the thermo-mechanical coupling characteristics were studied.And the experimental platform of the linear rolling guide way was built to verify the correctness of the theoretical modeling and simulation analysis.The main research work of the paper was summarized as follows.(1)The literature on the linear rolling guideway research at home and abroad was referred and summarized and the research content and method of the paper were determined.(2)The frictional characteristics of the guideway was studied.The theoretical model of the the linear rolling guideway contact zone was built and the mechanism of friction generating in the contact zone of the linear rolling guideway was studied,and then further study on the relationship model among the external force,contact force of guide pairs and friction force was carried out.The basic parameters of the contact zone were solved which provided basic data for finite element analysis of the linear rolling guideway later.(3)The theoretical models of temperature field and stress field of linear rolling guide pairs were established.Based on differential equations of heat conduction of the linear rolling guideway,the temperature field model and stress field model were established.The temperature distribution rules as well as the stress evolutions with the temperature of the guide pairs were studied which provided a theoretical basis for further study on thermo-mechanical coupling characteristics of the guideway.(4)The simulation analysis model of the thermo-mechanical coupling characteristic of the linear rolling guideway was established based on the large finite element analysis software.The temperature field distribution of the linear rolling guide pairs was caculated and the temperature evolution with time was studied.By comparing the stress and displacement results between the structure analysis and thermo-mechanical coupling analysis respectively,the mutual influences between the thermal properties and mechanical properties was researched.(5)Experimental device for measuring thermal characteristics of the linear rolling guideway was established to study thermal characteristics of the guideway experimentally.The temperature of the guideway under the real operating conditions was measured with platinum thermal resistance sensor and then finite element simulation results were compared with the experimental data.From the above,a basis for further research on the influence of the guideway on the machine tool was provided through the 'study of the thermo-mechanical coupling characteristics of the linear rolling guideway in the paper,which has a certain guiding significance for the machine tool manufacturers to choose the guideway properly.